What Makes a Great Backend Engineer? Types, Skills, and Code Smells

Programmers vary widely in skill and quality; evaluating a developer’s performance requires considering maintainability, extensibility, availability, stability, performance, security, fault tolerance, and risk control.

Programmer Types

Theoretical : Strong theory and design skills, confident in proposals, but often writes messy, hard‑to‑maintain code.

Potential : Good business sense, clear design and debugging approach, produces high‑quality code and explores new technologies.

Surface : Completes requirements but writes buggy, hard‑to‑maintain code and rarely learns new tech.

Honest : Diligent, average code quality, low visibility, limited communication.

Guru : Excels in all areas, provides valuable advice, but very rare.

From a backend developer’s perspective.

Required Abilities for Backend Engineers

Basic Abilities

SQL injection, XSS, CSRF, HTTP hijacking, DDoS mitigation

Code standards, clear layering, logical clarity

Database operations, HTTP knowledge, packet capture and request simulation

Frontend/JS debugging via browser console

Security prevention

Advanced Abilities

High‑concurrency handling and optimization

Performance tuning (load speed, TPS improvement)

Requirement analysis and solution design

Abstract programming and appropriate design pattern usage

Module encapsulation, asynchronous and multithreaded programming

Cache usage (Redis, Memcached) and message queue middleware (RabbitMQ, Kafka, etc.)

Auxiliary Abilities

Understanding attacks to improve defense

Simulating requests to find vulnerabilities

Concurrent request testing to expose logic issues

Hands‑on experience with web crawling

Communication Ability

Team discussion of designs, sharing technical ideas

Proactive collaboration

Debugging Ability

Rapid response to issue feedback

Quick problem localization based on symptoms

Fast solution delivery and deployment

Learning Ability

Viewing programming languages as tools, learning through project practice

Researching cutting‑edge technologies and applying them

Multi‑language development (Python, Java, Node.js, PHP, etc.)

Anticipation Ability

Designing code for future extensibility

Architecting systems to support business growth

Architecture Ability

Layering, segmentation, distributed systems

Caching, clustering, asynchronous processing

Redundancy, automation, security

Bad Code Smells

Bad smell 1: Unclear layering, SQL concatenated in controller layer

Bad smell 2: Excessive function parameters

Bad smell 3: Overly deep nesting

Bad smell 4: Duplicate functionality with excessive depth

Conclusion

Regardless of your programmer type, uphold responsibility for your role.

Continuously reflect on past code, identify unreasonable designs, summarize, and solidify lessons.